This invention relates to a method of treating squamous cell carcinoma with recombinant human alpha interferon by administering the interferon directly into the carcinoma lesion, i.e. intralesionally.
Squamous cell carcinomas are cutaneous neoplasms found in humans and often arise in sun-damaged areas. Present treatment methods include various surgical techniques such as electrodesiccation and curettage, excision, cryosurgery and irradiation. Cure rates for the surgical techniques are generally quite good, however, non-surgical methods of therapy are generally thought to be more desirable.
Various efforts have been made to treat cancers by injecting interferon directly into the lesion. For example, Ikeda, Gan to Kagaku Ryoho, 12(4), 936-942 (1985) used recombinant interferon A to treat various malignant skin tumors and achieved low cure rates. None of the tumors treated were stated to be squamous cell carcinomas. Ikic et al., The Lancet, May 9, 1981, pages 1025-1027, treated squamous cell carcinoma with crude human leucocyte interferon. Ikic et al. did not use a purified interferon material, but used a material containing a mixture of leukocyte interferon components and non-interferon impurities.
Interferons are a family of proteins which exhibit antiviral activity against certain viruses and anticancer activity against certain cancers. There are three types of interferons; alpha or leukocyte interferon, beta or fibroblast interferon and gamma or immune interferon. Human alpha interferon is a naturally occurring mixture of at least eleven components including those designated alpha-1 interferon and alpha-2 interferon. Human alpha interferon exhibiting biological properties similar to those of naturally occurring human leukocyte interferon can be made by recombinant methods.
A number of alpha interferon species or components are known and are usually designated by a numeral after the Greek letter alpha, and all are contemplated for use in this invention. Thus, the species designated human alpha-1 interferon and human alpha-2 interferon (sometimes called human alpha-2 interferon which includes human alpha-2a and human alpha-2b interferon; USAN: Interferon Alfa-2 including Interferon alfa-2a and Interferon Alfa-2b) are contemplated, with human alpha-2 interferon preferred. Interferon alfa-2 can be produced in bacteria using recombinant techniques as disclosed in Rubenstein, Biochem. Biophys. Acta, 695, 5-16 (1982). In addition, interferon alfa-2 may be prepared by recombinant-DNA methods disclosed by Nagata et al., Nature, 284, 316-320 (1980), European patent 32,134 and U.S. Pat. No. 4,289,690. Various alpha-2-interferon species are disclosed in U.S. Pat. No. 4,503,035. Preferred for use in this invention is the human interferon alfa-2b (hIFN-.alpha.2b).